Some businesses have a need to monitor the locations of people or equipment. For example, hospitals might desire to monitor the location of doctors on call in the emergency room. Or, hospitals may desire to monitor the location of a patient with temporary or permanent memory loss, such as a patient with Alzheimer's disease, to aid in ensuring that the patient does not wander away from the hospital.
Infrared personnel locator systems are known in the art. U.S. Pat. No. 4,275,385 discloses such a system using a battery-powered transmitter unit which emits a periodic unique infrared identification code. U.S. Pat. No. 4,649,385 discloses a system for determining the location of a member of a class of transmitter-receivers.
One disadvantage of these systems is that the remote transmitter units are not designed to be worn by a person or otherwise used in environments such as hospitals where the units are susceptible to fluid exposure. Another drawback is that the units are typically user programmed with identification codes and other parameters by way of a physical connection or cabling to a programming device. Programming the identification code after connecting the cabling can be time consuming and cumbersome. Furthermore, to connect these cables, there must be a passageway between the cable and the receiver. Unfortunately, water and other fluids may enter this passageway and damage the internal electronics.